Patent application title: TAPERED ROLLER BEARING

Abstract:

A tapered roller bearing includes a cage 5 composed of a first annular
portion 20, a second annular portion 21 positioned on a larger-diameter
side of a tapered raceway surface 12 of an inner ring 2 in an axial
direction, and pillar portions that couple the first annular portion 20
and the second annular portion 21 to each other. A tapered roller contact
members 6 which has a portion in contact with a second end face 31, i.e.,
a larger-diameter end face of the tapered roller 3 and which is made from
a material having lubricating oil-permeating property is fixed to an
outer circumferential surface of the second annular portion 21 so as to
provide a clearance to an inner circumferential surface of an outer ring
1.

Claims:

1. A tapered roller bearing comprising:an inner ring having a tapered
raceway surface and a larger flange portion positioned on a
larger-diameter side of the tapered raceway surface;an outer ring having
a tapered raceway surface;a plurality of tapered rollers each of which
has a first end face, and a second end face positioned on a
larger-diameter side of the tapered raceway surface of the inner ring
further than the first end face in an axial direction of the inner ring,
and which are positioned between the tapered raceway surface of the inner
ring and the tapered raceway surface of the outer ring;a cage composed of
a first annular portion, a second annular portion positioned on the
larger-diameter side of the tapered raceway surface of the inner ring
further than the first annular portion in the axial direction, and pillar
portions which couple the first annular portion and the second annular
portion to each other; anda tapered roller contact member which is fixed
to a circumferential surface of the second annular portion so as to
provide a clearance to an inner circumferential surface of the outer
ring, and which has a portion in contact with the second end face of the
tapered roller, and moreover which is made from a material having
lubricating oil-permeating property.

2. The tapered roller bearing as claimed in claim 1, whereinthe tapered
roller contact member is present only at positions where the tapered
roller contact member roughly overlaps in the axial direction with the
plurality of tapered rollers, andat every position where the tapered
roller contact member is present in a circumferential direction of the
second annular portion, an axially inner end face of the tapered roller
contact member is positioned axially inner than an axially inner end face
of the second annular portion.

3. The tapered roller bearing as claimed in claim 1, whereinthe tapered
roller contact member is an annular member, andover an entire
circumference of the circumferential direction of the second annular
portion, an axially inner end face of the tapered roller contact member
is positioned axially inner than an axially inner end face of the second
annular portion.

Description:

TECHNICAL FIELD

[0001]The present invention relates to tapered roller bearings. In
particular, the invention relates to a tapered roller bearing which is
preferably used for rotatably supporting a pinion shaft in a vehicle-use
pinion shaft supporting device having the pinion shaft, such as
differential gear devices, transaxle devices or transfer devices.

BACKGROUND ART

[0002]Conventionally, there is provided a tapered roller bearing described
in JP 11-48805 A (Patent Literature 1) This tapered roller bearing has an
inner ring, an outer ring and tapered rollers. The inner ring has, on a
larger-diameter side of its tapered raceway surface, a larger flange
portion put into contact with larger-diameter end faces of the tapered
rollers. An inner circumferential surface of the inner ring is fixed to
the pinion shaft of the differential gear device, while an outer
circumferential surface of the outer ring is fixed to an annular
partition wall within the differential gear device.

[0003]In this tapered roller bearing, oil that has flowed up from a ring
gear side of the differential gear device via an oil passage is made to
flow, between the inner circumferential surface of the outer ring and the
outer circumferential surface of the inner ring, from an opening of a
smaller-diameter side of the tapered raceway surface of the inner ring to
an opening of a larger-diameter side of the tapered raceway surface of
the inner ring, so that the outer ring, the inner ring and the tapered
rollers are prevented from occurrence of seizures.

[0004]In such a background, for such oil lubrication type tapered roller
bearings as described above, there is a demand for largely reducing oil
stirring resistance to achieve a large reduction of torque. However, when
the quantity of oil flowing in the tapered roller bearing is limited to
an extremely small quantity to largely reduce the oil stirring
resistance, which is a major factor of torque, with a view to achieving a
large reduction of torque, it may occur that oil does not spread enough
to sliding portions between the larger flange portion of the inner ring
and the larger-diameter end faces of the tapered rollers, causing less
lubrication of those sliding portions.

[0005]Meanwhile, when enough quantity of oil to well lubricate the sliding
portions is fed into the tapered roller bearing, there would be torque
increases due to the oil stirring resistance, making it impossible to
achieve a large reduction of torque.

[0006]PATENT LITERATURE 1: JP 11-48805 A (FIG. 1)

SUMMARY OF INVENTION

Technical Problem

[0007]Accordingly, an object of the present invention is to provide a
tapered roller bearing which allows sliding portions between the larger
flange portion of the inner ring and the tapered rollers to be lubricated
with no problem and which, at the same time, allows a large reduction of
torque to be achieved.

Solution to Problem

[0008]In order to achieve the above object, according to the present
invention, there is provided a tapered roller bearing comprising:

[0009]an inner ring having a tapered raceway surface and a larger flange
portion positioned on a larger-diameter side of the tapered raceway
surface;

[0010]an outer ring having a tapered raceway surface;

[0011]a plurality of tapered rollers each of which has a first end face,
and a second end face positioned on a larger-diameter side of the tapered
raceway surface of the inner ring further than the first end face in an
axial direction of the inner ring, and which are positioned between the
tapered raceway surface of the inner ring and the tapered raceway surface
of the outer ring;

[0012]a cage composed of a first annular portion, a second annular portion
positioned on the larger-diameter side of the tapered raceway surface of
the inner ring further than the first annular portion in the axial
direction, and pillar portions which couple the first annular portion and
the second annular portion to each other; and

[0013]a tapered roller contact member which is fixed to a circumferential
surface of the second annular portion so as to provide a clearance to an
inner circumferential surface of the outer ring, and which has a portion
in contact with the second end face of the tapered roller, and moreover
which is made from a material having lubricating oil-permeating property.

[0014]The present inventors have verified that when a tapered roller
bearing (having no tapered roller contact member) is installed in an
environment in which lubricating oil flows from an opening of a
smaller-diameter side of an inner ring to an opening of a larger-diameter
side of the inner ring between the outer ring and the inner ring, a flow
rate of lubricating oil that flows in at an inlet-side opening from
radial inward of a cage and flows out at an outlet-side opening from
radial outward of the cage, although varying depending on specifications,
is about 75% of a total quantity. It has also been verified that a flow
rate of the lubricant that flows in at the inlet-side opening from radial
inward of the cage and flows out at the outlet-side opening from radial
inward of the cage is about 12.5% of a total quantity, and that a flow
rate of the lubricant that flows in at the inlet-side opening from radial
outward of the cage and flows out at the outlet-side opening from radial
outward of the cage is about 12.5% of a total quantity.

[0015]Then, the inventors have found that in order to suppress to the
utmost the lubricating-oil stirring resistance that could cause torque
increases and, at the same time, to prevent occurrence of seizures on the
tapered roller guide surface of the larger flange portion that is most
liable to occurrence of seizures, it is effective that the quantity of
lubricating oil within the tapered roller bearing is decreased to a lower
level without causing any disturbance for lubricating oil which flows out
at the outlet-side opening from radial outward of the cage and which
occupies about 87.5% (75%+12.5%) of a total flow quantity, while part of
the lubricating oil which flows out in a larger quantity from radial
outward of the cage is fed to a second end face of a tapered roller (one
of two end faces of the tapered roller positioned on the larger-diameter
side of the tapered raceway surface of the inner ring). In addition, as a
matter of course, part of the lubricating oil that flows out from radial
inward of the cage may be fed to the second end face of the tapered
roller.

[0016]According to this invention, since the tapered roller bearing
includes the tapered roller contact member which is fixed to the
circumferential surface of the second annular portion so as to provide
the clearance to the inner circumferential surface of the outer ring and
which has the portion in contact with the second end face of the tapered
roller and moreover which is made from the material having oil-permeating
property, lubricating oil is allowed to flow out of the bearing from
between the tapered roller contact member and the outer ring, while the
lubricating oil that has permeated into the tapered roller contact member
can be fed to the second end face of the tapered roller. As a result of
this, the quantity of lubricating oil that reaches the tapered roller
guide surface of the larger flange portion of the inner ring can be
increased. Thus, the lubricating-oil stirring resistance that could cause
torque increases can be suppressed, while occurrence of seizures on the
tapered roller guide surface of the larger flange portion of the inner
ring can be suppressed.

[0017]In one embodiment, the tapered roller contact member is present only
at positions where the tapered roller contact member roughly overlaps in
the axial direction with the plurality of tapered rollers, and

[0018]at every position where the tapered roller contact member is present
in a circumferential direction of the second annular portion, an axially
inner end face of the tapered roller contact member is positioned axially
inner than an axially inner end face of the second annular portion.

[0019]According to the embodiment, since the tapered roller contact member
is present only at such positions as to roughly overlap in the axial
direction with the plurality of tapered rollers and roughly absent at
such positions as not to overlap in the axial direction with a plurality
of tapered rollers, it becomes achievable to cut down the material cost
of the tapered roller contact member, and moreover disturbance in outflow
of the lubricating oil is roughly avoided at positions where the tapered
roller contact member roughly does not overlap in the axial direction
with the plurality of tapered rollers. Thus, the oil stirring resistance
can be reduced.

[0020]Also, according to the embodiment, since the axially inner end face
of the tapered roller contact member is positioned axially inner than the
axially inner end face of the second annular portion at every position
where the tapered roller contact member is present in the circumferential
direction of the second annular portion, the lubricating oil can
efficiently be fed to the second end face of the tapered roller, so that
seizures of the larger flange portion of the inner ring can efficiently
be suppressed.

[0021]In one embodiment, the tapered roller contact member is an annular
member, and

[0022]over an entire circumference of the circumferential direction of the
second annular portion, an axially inner end face of the tapered roller
contact member is positioned axially inner than an axially inner end face
of the second annular portion.

[0023]According to the embodiment, since the tapered roller contact member
is the annular member, a large quantity of lubricating oil can be
received without being prevented by the tapered rollers at portions of
the tapered roller contact member other than those at positions where the
tapered roller contact member overlaps in the axial direction with the
plurality of tapered rollers. Moreover, since the axially inner end face
of the tapered roller contact member is positioned axially inner than the
axially inner end face of the second annular portion over the entire
circumference of the circumferential direction of the second annular
portion while the portions of the tapered roller contact member axially
overlapping with the tapered roller are in contact with the tapered
roller, lubricating oil can be conducted smoothly to the second end face
of the tapered roller from portions of the tapered roller contact member
other than its axially overlapping positions via positions where the
tapered roller contact member axially overlaps with the plurality of
tapered rollers. Thus, a further suppression of seizures on the tapered
roller guide surface of the larger flange portion can be achieved.

ADVANTAGEOUS EFFECTS OF INVENTION

[0024]According to this invention, since the tapered roller bearing
includes the tapered roller contact member which is fixed to the
circumferential surface of the second annular portion so as to provide a
clearance to the inner circumferential surface of the outer ring and
which has a portion in contact with the second end face of the tapered
roller and moreover which is made from a material having oil-permeating
property, lubricating oil is allowed to flow out of the bearing from
between the tapered roller contact member and the outer ring, while the
lubricating oil that has permeated into the tapered roller contact member
can be fed to the second end face of the tapered roller and, therefore,
the quantity of Lubricating oil that reaches the tapered roller guide
surface of the larger flange portion of the inner ring can be increased.
Thus, the lubricating-oil stirring resistance that could cause torque
increases can be suppressed, while occurrence of seizures on the tapered
roller guide surface of the larger flange portion of the inner ring can
be suppressed.

BRIEF DESCRIPTION OF DRAWINGS

[0025]FIG. 1 is an axial sectional view of a tapered roller bearing
according to a first embodiment of the invention;

[0026]FIG. 2 is an enlarged sectional view of a vicinity of a second
annular portion in FIG. 1;

[0027]FIG. 3 is a view of the tapered roller bearing of the first
embodiment as viewed from axial outward of a larger-diameter side end
face of a tapered raceway surface of an inner ring;

[0028]FIG. 4 is a view of a tapered roller bearing of a second embodiment
as viewed from axial outward of a larger-diameter side end face of a
tapered raceway surface of an inner ring;

[0029]FIG. 5 is a view of a modification of the invention corresponding to
FIG. 3 in a case where a tapered roller contact member is fixed to an
outer circumferential surface of a second annular portion of a cage;

[0030]FIG. 6 is an axial sectional view of a tapered roller bearing
according to a third embodiment of the invention;

[0031]FIG. 7 is a view of the tapered roller bearing of the third
embodiment as viewed from axial outward of a larger-diameter side end
face of a tapered raceway surface of an inner ring;

[0032]FIG. 8 is a view of a modification of the invention corresponding to
FIG. 7 in a case where a tapered roller contact member is fixed to an
inner circumferential surface of a second annular portion of a cage.

[0048]Hereinbelow, the present invention will be described in detail by
embodiments thereof illustrated in the accompanying drawings.

[0049]FIG. 1 is an axial sectional view of a tapered roller bearing
according to a first embodiment of the invention.

[0050]With this tapered roller bearing, a pinion shaft of a vehicle-use
pinion shaft supporting device under a lubricating condition requiring
use of a large quantity of relatively high-viscosity oil, such as
differential gear device, transaxle device or transfer device, is
supported so as to be rotatable relative to a housing of the vehicle-use
pinion shaft supporting device.

[0051]The tapered roller bearing includes an outer ring 1, an inner ring
2, a plurality of tapered rollers 3, a cage 5, and a tapered roller
contact member 6.

[0052]The outer ring 1 has a tapered raceway surface 11, while the inner
ring 2 has a tapered raceway surface 12, a smaller flange portion 13
positioned on a smaller-diameter side of the tapered raceway surface 12,
and a larger flange portion 14 positioned on a larger-diameter side of
the tapered raceway surface 12. Gear oil in the vehicle-use pinion shaft
supporting device as an example of lubricating oil flows from an opening
of a smaller-diameter side of the tapered raceway surface 12 of the inner
ring 2 to an opening of a larger-diameter side of the tapered raceway
surface 12 of the inner ring 2 between the outer ring 1 and the inner
ring 2.

[0053]Each of the tapered rollers 3 has a first end face 30 and a second
end face 31. The second end face 31 is positioned on the larger-diameter
side of the tapered raceway surface 12 of the inner ring 2 further than
the first end face 30 in an axial direction (more precisely, in the axial
direction of the inner ring 2). Each of the first end face 30 and the
second end face 31 has a circular shape. A diameter of the second end
face 31 is larger than a diameter of the first end face 30. The plurality
of tapered rollers 3 are arranged between the tapered raceway surface 11
of the outer ring 1 and the tapered raceway surface 12 of the inner ring
2 so as to be circumferentially spaced from one another in a state that
the tapered rollers 3 are held by the cage 5.

[0054]The cage 5 is composed of a first annular portion 20, a second
annular portion 21, and a plurality of pillar portions (not shown). The
second annular portion 21 is positioned on the larger-diameter side of
the tapered raceway surface 12 of the inner ring 2 further than the first
annular portion 20 in the axial direction. Each of the pillar portions
couples the first annular portion 20 and the second annular portion 21 to
each other. The plurality of pillar portions are arranged so as to be
spaced from one another in the circumferential direction of the first
annular portion 20. A portion surrounded by the first annular portion 20,
the second annular portion 21 and circumferentially neighboring two
pillar portions serves as a pocket in which a tapered roller 3 is housed.

[0055]The tapered roller contact member 6 is made from felt, which is an
example of materials having lubricating-oil permeability. The tapered
roller contact member 6 is fixed to the outer circumferential surface of
the second annular portion 21 of the cage 5 by adhesive with a clearance
provided to the inner circumferential surface of the outer ring 1. As
shown in FIG. 1, an axially inner end face of the tapered roller contact
member 6 is positioned axially inner than an axially inner end face of
the second annular portion 21. An axially inner end portion of the
tapered roller contact member 6 is in contact with the second end face
(larger-diameter end face) 31 of the tapered roller 3.

[0056]FIG. 2 is an enlarged sectional view of a vicinity of the second
annular portion 21 in FIG. 1. Given a thickness t (mm) of the tapered
roller contact member 6 and a distance (more precisely, minimum distance)
d (mm) between the second annular portion 21 and the inner
circumferential surface of the outer ring 1, it holds that t≦d/2.

[0057]With such an arrangement as described above, gear oil that has
reached a larger-diameter side end portion of the tapered raceway surface
11 in the inner circumferential surface of the outer ring 1 along the
inner circumferential surface of the outer ring 1 by pumping action is
allowed to flow out of the bearing without being prevented by the tapered
roller contact member 6, so that a reduction of gear-oil stirring
resistance can be achieved.

[0058]FIG. 3 is a view of the tapered roller bearing of the first
embodiment as viewed from axial outward of an end face 40 of a
larger-diameter side (see FIG. 1) of the tapered raceway surface 12 of
the inner ring 2.

[0059]As shown in FIG. 3, the tapered roller contact member 6 is composed
of a plurality of portions placed with specified intervals in the
circumferential direction. The tapered roller contact member 6 is present
only at such positions as to generally overlap with the plurality of
tapered rollers 3 in the axial direction.

[0060]More precisely, the tapered roller contact member 6 is present only
at portions in the circumferential direction of the second annular
portion 21 facing the pockets. That is, assuming that circumferentially
neighboring pillar portions are a first pillar portion and a second
pillar portion, the tapered roller contact member 6 is present over a
range from a second pillar portion-side edge of the first pillar portion
to a first pillar portion-side edge of the second pillar portion in the
second annular portion 21 along the circumferential direction.

[0061]In every portion in the circumferential direction where the tapered
roller contact member 6 is present, the tapered roller contact member 6
has a portion positioned axially inner than the axially inner end face of
the second annular portion 21. A tapered roller 3 side end face of the
tapered roller contact member 6 in a portion over which the tapered
roller contact members 6 overlaps with the tapered roller 3 in the axial
direction is in contact with the tapered roller 3.

[0062]According to the tapered roller bearing of the first embodiment, the
tapered roller bearing has a portion which is fixed to the outer
circumferential surface of the second annular portion 21 in contact with
the second end face 31 of the tapered roller 3 so that gear oil as
lubricating oil is allowed to flow out of the bearing from between the
tapered roller contact member 6 and the inner circumferential surface of
the outer ring 1 while a clearance is provided to the inner
circumferential surface of the outer ring 1, and moreover the tapered
roller bearing further includes the tapered roller contact member 6 made
from felt having oil-permeating property. Therefore, the gear oil that
has permeated into the tapered roller contact member 6 can be fed to the
second end face 31 of the tapered rollers 3. Thus, by rotation and
revolution of the tapered rollers 3, the gear oil can be conducted along
the tapered roller guide surface of the larger flange portion 14 of the
inner ring 2, so that the quantity of the gear oil that reaches the
tapered roller guide surface of the larger flange portion 14 of the inner
ring 2 can be increased effectively. Accordingly, since the larger flange
portion can reliably be lubricated even with less quantities of gear oil,
gear-oil stirring resistance due to large quantities of gear oil can be
suppressed, and moreover occurrence of seizures on the tapered roller
guide surface of the larger flange portion 14 of the inner ring 2 can be
suppressed.

[0063]Also, according to the tapered roller bearing of the first
embodiment, the tapered roller contact member 6 is generally absent at
positions where the tapered roller contact member 6 does not overlap in
the axial direction with a plurality of tapered rollers 3, and the
tapered roller contact member 6 is generally absent at positions where
the gear oil as lubricating oil is allowed to flow out of the bearing
without being disturbed by the tapered rollers 3, i.e., positions where
the tapered roller contact member 6 does not overlap in the axial
direction with a plurality of tapered rollers 3. Thus, at positions where
the tapered roller contact member 6 does not overlap in the axial
direction with the tapered rollers 3, the gear oil is allowed to
efficiently flow out of the bearing generally without being prevented by
the tapered roller contact member 6. Therefore, oil stirring resistance
can be reduced, allowing a large reduction of torque to be achieved.
Moreover, the material cost of the tapered roller contact member 6 can be
cut down.

[0064]Also, according to the tapered roller bearing of the first
embodiment, the tapered roller contact member 6 is present only at
positions where the tapered roller contact member 6 roughly overlaps in
the axial direction with a plurality of tapered rollers 3, and the
axially inner end face of the tapered roller contact member 6 is
positioned axially Inner than the axially inner end face of the second
annular portion 21 for every position where the tapered roller contact
member 6 is present in the circumferential direction of the second
annular portion 21. Therefore, gear oil can efficiently be fed to the
second end face 31 of the tapered roller 3, so that seizures of the
larger flange portion of the inner ring 2 can efficiently be suppressed.

[0065]In addition, although the material of the tapered roller contact
member 6 is felt in the tapered roller bearing of the first embodiment,
the invention allows any material to be used as the material of the
tapered roller contact member as far as the material has oil-permeating
property, such as cotton and sponge. Also, as the material of the tapered
roller contact member, a material that can be impregnated with oil and
that allows oil to be oozed by contact is particularly preferably.

[0066]FIG. 4 is a view of a tapered roller bearing according to a second
embodiment, as viewed from axial outward of a larger-diameter side end
face 40 of the tapered raceway surface of the inner ring 2, corresponding
to FIG. 3 of the tapered roller bearing of the first embodiment.

[0067]In the tapered roller bearing of the second embodiment, its
component members similar to those of the tapered roller bearing of the
first embodiment are designated by like reference signs and their
description is omitted. Also, in the tapered roller bearing of the second
embodiment, descriptions of functional effects and modifications common
to the tapered roller bearing of the first embodiment are omitted, and
their component members and functional effects different from those of
the tapered roller bearing of the first embodiment only will be
described.

[0068]In the second embodiment, a tapered roller contact member 106 made
from felt is an annular member, which is fixed to an outer
circumferential surface of the second annular portion 21 over an entire
circumference of the second annular portion 21. An axially inner end face
of the tapered roller contact member 106 is positioned axially inner than
an axially inner end face of the second annular portion 21 over the
entire circumference. In the axial direction, a tapered roller 3 side end
face of the tapered roller contact member 6 overlapping with the tapered
rollers 3 is in contact with the second end face 31 of the tapered roller
3.

[0069]According to the tapered roller bearing of the second embodiment,
since the tapered roller contact member 106 is an annular member, large
quantities of lubricating oil can be received without being prevented by
the tapered rollers 3 at portions of the tapered roller contact member
106 other than its positions where the tapered roller contact member 106
overlaps in the axial direction with a plurality of tapered rollers 3.
Also, since the axially inner end face of the tapered roller contact
member 106 is positioned axially inner than the axially inner end face of
the second annular portion 21 over the entire circumference of the second
annular portion 21 and the portions of the tapered roller contact member
106 overlapping in the axial direction with the tapered rollers 3 are in
contact with the tapered rollers 3, lubricating oil can be conducted to
the second end face 31 of the tapered rollers 3 effectively and smoothly
from portions of the tapered roller contact member 106 other than its
axially overlapping portions, via the positions where the tapered roller
contact member 106 overlaps with a plurality of tapered rollers 3.
Accordingly, seizures on the tapered roller guide surface of the larger
flange portion of the inner ring 2 can be suppressed with more
reliability. Also, since the tapered roller contact member 106 is an
annular integrated member, its easier assembling and stronger adhesion
with the cage can be obtained.

[0070]It is needless to say that the position where the tapered roller
contact member is present in the circumferential direction is not limited
to those described in the first and second embodiments. For example, the
position where the tapered roller contact member is present may be an
entirety of the second annular portion in its circumferential direction
except its portion overlapping in the axial direction with one pillar
portion. In this case, the tapered roller contact member can be fitted
promptly and easily to the second annular portion so as to be wound
around the second annular portion.

[0071]Also, a tapered roller contact member in contact with only part of a
plurality of tapered rollers may be fixed to the outer circumferential
surface of the cage. More specifically, given a count N (where N is a
natural number) of the tapered rollers included in the tapered roller
bearing, a tapered roller contact member composed of M portions that are
in contact with only M tapered rollers, satisfying that N>M (M is a
natural number), may be fixed to the outer circumferential surface of the
cage.

[0072]Also, in this case, with regard to the portion of the tapered roller
contact member in contact with each tapered roller, a portion smaller
than the entirety of the axially inner end face of the tapered roller
contact member may be in contact with the second end face of the tapered
roller as shown in FIG. 3. Furthermore, as shown in FIG. 5, with regard
to a portion 206 of the tapered roller contact member in contact with
each tapered roller 203, the entirety of the axially inner end face of
the portion 206 of the tapered roller contact member may be in contact
with a second end face 231 of the tapered roller 203.

[0073]Thus, the tapered roller contact member may be fixed to any position
on the outer circumferential surface of the second annular portion only
if the tapered roller contact member has a portion in contact with the
end face of the tapered roller.

[0074]Further, only if the tapered roller contact member has a portion in
contact with the end face of the tapered roller, the tapered roller
contact member does not need to be fixed to the outer circumferential
surface of the second annular portion and may be fixed to an inner
circumferential surface of the second annular portion.

[0075]FIG. 6 is an axial sectional view of a tapered roller bearing
according to a third embodiment of the invention. The tapered roller
bearing of the third embodiment differs from the tapered roller bearing
of the first embodiment only in that a tapered roller contact member 306
is not fixed to the outer circumferential surface of the second annular
portion 21 of the cage 5, but fixed to an inner circumferential surface
47 of the second annular portion 21 of the cage 5.

[0076]In the tapered roller bearing of the third embodiment, its component
members similar to those of the tapered roller bearing of the first
embodiment are designated by like reference signs and their description
is omitted. Also, in the tapered roller bearing of the third embodiment,
description of functional effects and modifications common to the tapered
roller bearing of the first embodiment as well as functional effects and
modifications common to the tapered roller bearing of the second
embodiment is omitted, and only component members, functional effects and
modifications different from those of the tapered roller bearings of the
first and second embodiments will be described.

[0077]The tapered roller contact member 306 of the tapered roller bearing
of the third embodiment is made from felt, which is an example of
materials having lubricating-oil permeability.

[0078]As shown in FIG. 6, the tapered roller contact member 306 is fixed
to the inner circumferential surface 47 of the second annular portion 21
of the cage 5 by adhesive. An axially inner end face of the tapered
roller contact member 306 is positioned axially inner than the axially
inner end face of the second annular portion 21. An axially inner end
portion of the tapered roller contact member 306 is in contact with the
second end face (larger-diameter end face) 31 of the tapered roller 3.

[0079]FIG. 7 is a view of the tapered roller bearing of the third
embodiment, as viewed from axial outward of the larger-diameter side end
face 40 (see FIG. 6) of the tapered raceway surface 12 of the inner ring
2.

[0080]As shown in FIG. 7, the tapered roller contact member 306 is
composed of a plurality of portions arranged with specified intervals in
the circumferential direction. The tapered roller contact member 306 is
present only at such positions as to roughly overlap in the axial
direction with a plurality of tapered rollers 3.

[0081]More precisely, the tapered roller contact member 306 is present
only at portions of the second annular portion 21 facing the pockets in
the circumferential direction. That is, assuming that circumferentially
neighboring pillar portions are a first pillar portion and a second
pillar portion, the tapered roller contact member 306 is present over a
range from a second pillar portion-side edge of the first pillar portion
to a first pillar portion-side edge of the second pillar portion in the
second annular portion 21 along the circumferential direction.

[0082]In every portion in the circumferential direction where the tapered
roller contact member 306 is present, the tapered roller contact member
306 has a portion positioned axially inner than the axially inner end
face of the second annular portion 21. A tapered roller 3 side end face
of the tapered roller contact member 306 which overlaps with the tapered
roller 3 in the axial direction is in contact with the tapered roller 3.

[0083]In some cases depending on specifications, a contact area between
the tapered roller contact member and the second end face of the tapered
roller can be made larger, allowing larger quantities of lubricating oil
to be fed to the second end face of the tapered roller, when the tapered
roller contact member is fixed to the inner circumferential surface of
the second annular portion of the cage, rather than when the tapered
roller contact member is fixed to the outer circumferential surface of
the second annular portion of the cage.

[0084]Also, in some cases depending on specifications, a distance from a
lubricating-oil feeding area of the second end face of the tapered roller
by the tapered roller contact member to a tapered roller guide surface of
the larger flange portion of the inner ring can be made shorter, helping
to suppress seizures on the tapered roller guide surface that is more
liable to seizures, when the tapered roller contact member is fixed to
the inner circumferential surface of the second annular portion of the
cage, rather than when the tapered roller contact member is fixed to the
outer circumferential surface of the second annular portion of the cage.

[0085]According to the tapered roller bearing of the third embodiment,
since the tapered roller contact member is fixed to the inner
circumferential surface of the second annular portion of the cage, the
seizure suppressing effect of the tapered roller bearing can be increased
in such cases as described above.

[0086]In the tapered roller bearing of the third embodiment, by the
tapered roller contact member 306, lubricating oil is fed from the inner
circumferential surface side of the second annular portion 21 of the cage
5 to the second end face 31 of every tapered roller 3. However, in the
present invention, by the tapered roller contact member, lubricating oil
may be fed from the inner circumferential surface side of the second
annular portion of the cage to only part of a plurality of tapered
rollers, i.e., to only M tapered rollers (where M is a natural number),
given a count N (where N is a natural number) of tapered rollers included
in the tapered roller bearing, satisfying a condition that N>M.

[0087]Also, in this case, with regard to the portion of the tapered roller
contact member in contact with each tapered roller, a portion of the
tapered roller contact member smaller than an entirety of the axially
inner end face of each tapered roller contact member may be in contact
with the second end face of the tapered roller as shown in FIG. 7.
Moreover, with regard to a portion 406 of the tapered roller contact
member in contact with each tapered roller 403, the entirety of the
axially inner end face of the portion 406 of each tapered roller contact
member may be in contact with a second end face 431 of the tapered roller
403 as shown in FIG. 8.

[0088]Further, on the inner circumferential surface of the second annular
portion of the cage, a tapered roller contact member may be fixed over
the entire circumference of the inner circumferential surface.

[0089]In addition, the tapered roller contact member may be provided so as
to have a portion fitted to the outer circumferential surface of the
second annular portion and a portion fitted to the inner circumferential
surface of the second annular portion.

[0090]The tapered roller contact member may be fixed at any position on
either the outer circumferential surface or the inner circumferential
surface of the second annular portion only if the tapered roller contact
member has a portion in contact with the second end face of the tapered
roller.